Adjustable supporting stand

ABSTRACT

An adjustable supporting stand includes a main body with a receiving room, a slidable module disposed in the receiving room, a supporting holder assembled on the slidable module, a gear set connected to the supporting holder, and an elastic member disposed on the main body. The gear set has at least one first gear and a second gear, and the first gear is smaller than the second gear. One end of the elastic member is fixed on the main body and another end of the elastic member is connected to the second gear.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of prior U.S. applicationSer. No. 12/905,151, filed on Oct. 15, 2010, currently pending, thecontents of which are incorporated herein in by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The instant disclosure relates to an adjustable supporting stand; inparticular, an adjustable supporting stand characterized in reducing theelongation of the elastic member.

2. Description of Related Art

Monitor usually stands on a surface by a supporting stand. However, thetraditional stand does not provide height adjustment and the user cannot adjust the position of the monitor. Recently, adjustable supportingstand has been developed so that the user can change the monitor to adesired position or height to meet the requirement of user's view.

In the traditional adjustable stand structure, a movable member and aspring are used for adjusting the position of the monitor. The movablemember can slide upward or downward on the stand. One end of the springconnects to a pivoting shaft of the stand and the other end connects tothe movable member. The monitor is assembled to the movable member. Theuser can press the movable member so as to adjust the position of themonitor. When the user stop forcing the movable member, the monitor isset vertically by the balance between the weight of the monitor and theelastic force of the spring. For example, when the user forces to liftthe monitor, the monitor can be lifted to a desired position. In otherwords, by using the cooperation of the movable member and the spring,the act of adjusting the monitor is achieved.

However, with the increasing weight and size of the monitor, the forceprovided by the spring is not enough to support the monitor.Furthermore, the elongation of the spring is equal to the moved distanceof the monitor in the above mentioned structure, such that the elasticfatigue of the spring occurs easily with heavier monitor. As a result,the stand would fail to provide the adjusting function if the spring isbroken.

Consequently, with regard to the resolution of defects illustratedhereinbefore, the inventors of the instant disclosure propose areasonably and effectively designed solution for effectively eliminatingsuch defects.

SUMMARY OF THE INVENTION

The objective of the instant disclosure is to provide an adjustablesupporting stand having a gear set to reduce the elongation of theelastic member. Thus, the elastic member is protected from failure.

The objective of the instant disclosure is to provide a stepless anduniversal supporting stand.

To achieve the objective described as above, the instant disclosurediscloses an adjustable supporting stand, which comprises: a main body;a slidable module disposed on the main body; a supporting holder mountedon the slidable module, wherein the supporting holder slides relativelyto the main body; a gear set connected to the supporting holder, whereinthe gear set has a first gear connected to the supporting holder and asecond gear engaged with the first gear, and the first gear is smallerthan the second gear; and an elastic member disposed on the main body,wherein the elastic member has a first end and a second end oppositethereof. The first end is adjustably fixed on the main body, and thesecond end is connected to the second gear.

In the instant disclosure, the smaller first gear turns because of themovement of the supporting holder. Simultaneously, the larger secondgear is driven by the first gear. However, the second gear makes lessrevolution than the first gear. As a result, the elastic member which isforced to elongate by the turning of the second gear has a shorterelongation than the movement distance of the supporting holder. Thus,the elastic member is protected from elastic fatigue and the stand isprevented form failure.

In an exemplary embodiment, two such gear sets are provided. Forexample, a second gear makes less revolution than the first gear and afourth gear makes less revolution than the third gear when the secondgear is driving the third gear. Therefore, the elastic member which isforced to elongate by the turning of the fourth gear has an even shorterelongation than the movement distance of the supporting holder.Similarly, the elastic member is protected from elastic fatigue.

Accordingly, the elongation of the elastic member due to the slidingdistance of the supporting holder is reduced. Therefore, the lifetime ofthe elastic member and the reliability of the adjustable supportingstand are improved.

In order to further appreciate the characteristics and technicalcontents of the instant disclosure, references are hereunder made to thedetailed descriptions and appended drawings in connection with theinstant disclosure. However, the appended drawings are merely shown forexemplary purposes, rather than being used to restrict the scope of theinstant disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a structural diagram of the adjustable supporting stand at ahome position according to the instant disclosure.

FIG. 1B is a front view of the adjustable supporting stand at a homeposition according to the instant disclosure.

FIG. 2A is a structural diagram of the adjustable supporting stand at asecond position according to the instant disclosure.

FIG. 2B is a front view of the adjustable supporting stand at a secondposition according to the instant disclosure;

FIG. 3 is a structural diagram of the movement of the supporting holderaccording to the instant disclosure.

FIG. 4 is a front view of the adjustable supporting stand of a secondembodiment according to the instant disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The instant disclosure provides an adjustable supporting stand which maybe used to adjust the position of a display device. The gear set and theelastic member of the adjustable supporting stand are used to move thedisplay device. In the instant disclosure, the gear set includes abigger gear and a smaller gear to reduce the elongation of the elasticmember. Therefore, the elastic member is protected from failure and thelifetime of the supporting stand is increased.

Please refer to FIGS. 1A to 1B and FIGS. 2A to 2B. The adjustablesupporting stand has a main body 10, a slidable module 11 disposed onthe main body 10, a supporting holder 12 disposed on the slidable module11, a gear set 13 connected to the supporting holder 12, and an elasticmember 14 disposed on the main body 10. In the embodiment, the main body10 has a receiving room 101 for accommodating the above components. Forexample, the slidable module 11 is mounted inside the main body 10, suchthat the slidable module 11 is received inside the receiving room 101.On the other hand, the gear set 13 and the elastic member 14 are alsoaccommodated in the receiving room 101. The supporting holder 12 can bemounted on the slidable module 11. For example, the slidable module 11can include at least two tracks 111 and the supporting holder 12 isslidable about the tracks 11. In other words, the supporting holder 12can slide upward or downward by the function of the tracks 111. Thesupporting holder 12 is partially extended out of the receiving room101, such that the display device or another device can be mounted orassembled to the supporting holder 12. In another embodiment, theslidable module 11 can include groove and slidable member. For example,the inner surface of the main body 10 can have grooves and two sides ofthe supporting holder 12 has corresponding slidable members, such thatthe supporting holder 12 slides along the grooves with the combinationof the grooves and slidable members.

The gear set 13 and the elastic member 14 are constructed as a forcemodule to force on the supporting holder 12. The gear set 13 connects toand moves with the supporting holder 12. The gear set 13 has at leastone first gear 131 and one second gear 132 engaged with the first gear131, and the first gear 131 is smaller than the second gear 132. Thesupporting holder 12 connects with the first gear 131 (i.e., a gear ofsmaller size). A first end 141 of the elastic member 14 is adjustablyfixed on the main body 10, and a second end 142 of the elastic member 14is connected to the second gear 132 (i.e., the gear of larger size). Inthe embodiment, when the supporting holder 12 slides downward, the firstgear 131 and the second gear 132 of the gear set 13 rotate andsimultaneously the elastic member 14 is extended. Because of the sizedifference of the first gear 131 and the second gear 132, the firstrotated gear (i.e., the first gear 131) has longer rotation path thanthe second rotated gear (i.e., the second gear 132). Thus, the elasticmember 14 which is forced to elongate by the second gear 132 withshorter rotation path has small elongation. Accordingly, the elasticmember 14 elongates with shorter length than the traditional spring sothat the elastic member 14 is protected from elastic fatigue.

In the embodiment, the first gear 131 is assembled on a turning plate130, and the first gear 131 and the turning plate 130 rotate coaxially.A connection member 15, for example a rope, is connected in between theturning plate 130 and the supporting holder 12. When the supportingholder 12 slides downward, the connection member 15 is forced toelongate so that the turning plate 130, the first gear 131, and thesecond gear 132 rotate simultaneously because of the elongation of theconnection member 15. As discussed above, the elongation of the elasticmember 14 is reduced so as to protect the elastic member 14 due to thegear difference between the first gear 131 and the second gear 132.Please note that the turning plate 130 is used to carry the first gear131 and engage to the connection member 15, but the shape or thestructure of the turning plate 130 is not restricted thereby. On theother hand, the turning plate 130 and the first gear 131 may beintegrally formed or be assembled with each other.

For further reducing the elongation of the elastic member 14, the gearset 13 may have a third gear 133 and a fourth gear 134. The third gear133 is assembled on and rotates coaxially with the second gear 132. Thefourth gear 134 is engaged with the third gear 133 and has a pivotingshaft 135 thereon, and the second end 142 of the elastic member 14connects to the pivoting shaft 135. Moreover, the third gear 133 issmaller than the second gear 132 and the fourth gear 134 is larger thanthe third gear 133. Therefore, the movement distance of the supportingholder 12 is transmitted to the elastic member 14 through two sets ofsmall gear and large gear (i.e., the first gear 131 and the second gear132; the third gear 133 and the fourth gear 134) so that the elongationof the elastic member 14 is further reduced.

In an exemplary embodiment, the adjustable supporting stand of theinstant disclosure can be assembled with a display screen. For example,the display screen is assembled on or screwed to the supporting holder12 and the display screen can slide upward or downward because of theslidable module 11 so as to adjust the position thereof. The displayscreen can be hold at desired height due to the torque balance between atorque of a net force of display screen weight and friction, and atorque of the resilient force of the elastic member 14. In detail, thesupporting holder 12 connects to the turning plate 130 via the rope(i.e., the connection member 15) and the rope may pass through a fixedpulley. While forcing on the display screen which is fixed on thesupporting holder 12, the downward movement distance of the supportingholder 12 is transmitted in sequence to the rope, the turning plate 130connected to the rope, the first gear 131 coaxially rotating with theturning plate 130, the second gear 132 engaged with the first gear 131,the third gear 133 coaxially rotating with the second gear 132, thefourth gear 134 and at last to the elastic member 14. Because of thegear ratio of the first and second gear 131 and 132 and the gear ratioof the third and forth gear 133 and 134, the elongation of the elasticmember 14 is much less than the sliding distance of the supportingholder 12. In other words, the elastic member 14 is protected and haslong lifetime due to the short elongation after being forced. When theuser stops to force on the display screen, the torque applied by the netforce of weight of the display screen and the friction force, and thetorque applied by the elastic restoring force of the elastic member 14are balanced so that the display screen is positioned on a predeterminedheight. In detail, the torque applied by the elastic restoring force ofthe elastic member 14 is a clockwise torque which is measured bycomputing the cross-product of the elastic restoring force vector andthe radius vector of the fourth gear 134. The torque applied by the netforce of weight of the display screen and the friction force is acounterclockwise torque which is measured by computing the cross-productof the net force vector and the radius vector of the turning plate 130.Using this mechanism of balancing torque, the display screen on thesupporting holder 12 can be steplessly positioned in any desiredposition between the sliding ranges defined by the slidable module 11.

For lifting the display screen, the user may force on the display screento slide the supporting holder 12 upward. The lifting force and theelastic restoring force of the elastic member 14 drive the displayscreen and the supporting holder 12 to move upward. When the user stopsto force on the display screen, the display screen is positioned again.

On the other hand, for increasing the friction while the supportingholder 12 is sliding, the supporting holder 12 further has a frictionmember 16, such as rubber, and the friction member 16 may contact theinner surface of the main body 10. Therefore, the friction member 16provides friction so as to improve the stability of the supportingholder 12.

The stand further has a torque-adjusting member 17 which is used toadjust the torque of the elastic member 14 for display devices ofdifferent sizes or weights; in other words, the instant stand isuniversal for display devices of different sizes or weights. In theexemplary embodiment, the torque-adjusting member 17 may be a screwdisposed on the main body 10. The first end 141 of the elastic member 14connects to the end of the screw; therefore, the position of the firstend 141 of the elastic member 14 can be adjusted by changing the heightof the end of the screw. As a result, the elastic member 14 may outputdifferent torques to apply for the display devices of different sizes orweights. While a heavier display screen is mounted on the supportingholder 12, the elastic member 14 has a elongation to apply larger torqueto balance the torque of the display screen.

Please refer to FIG. 4; the smaller first gear 131 assembled on aturning plate 130 is directed engaged with the larger fourth gear 134without the second gear 132 and the third gear 133. Thus, the elongationof the elastic member 14 is reduced so as to protect the elastic member14 due to the gear difference between the first gear 131 and the fourthgear 134.

In further detail, when a display device of desired size/weight (e.g., a32 inch LCD TV) is chosen by a user, the torque-adjusting member 17 maybe used to adjust the position of the first end 141 of the elasticmember 14 so as to elongate the elastic member 14. Thus, the elasticmember 14 can provide a first resilient force. Please note that thesecond end 142, as shown in FIG. 1A, is located as the same horizontallevel with the rotary shaft of the fourth gear 134. A first positiveforce arm vertical to the first resilient force is defined as aprojection length of the radius of the fourth gear 134 (i.e., the lengthbetween the second end 142 and the rotary shaft of the fourth gear 134)on the horizontal axis and the first positive force arm is the greatestforce arm while the fourth gear 134 rotating. When the display device ismounted on the supporting holder 12, a first torque by acting the firstresilient force on the first positive force arm may be substantiallyequal to the torque by applying the net force of the weight of themounted display device and the friction force on the horizontal radiusof the turning plate 130. Therefore, the mounted display device on thesupporting holder 12 can be retained at a first position (e.g., thehighest position of the instant stand) due to the torque balance.

As shown in FIG. 2B, when the user polls down the mounted display devicefrom the first position to a second position, the second end 142 of theelastic member 14 move toward the rotary shaft of the fourth gear 134due to the counterclockwise rotation of the fourth gear 134.Accordingly, the elastic member 14 is further elongated and has a secondresilient force. At this time, a second positive force arm vertical tothe second resilient force, which is defined as a projection length ofthe radius of the fourth gear 134 (i.e., the length between the secondend 142 and the rotary shaft of the fourth gear 134) on the horizontalaxis, is reduced and smaller than the first positive force arm. Thatmeans the first positive force arm is the largest force arm, as thesupporting holder 12 is located at the highest position. Therefore, asecond torque by acting the second resilient force on the secondpositive force arm may be substantially equal to the torque by applyingthe net force of the weight of the mounted display device and thefriction force on the horizontal radius of the turning plate 130. Pleasenote that the friction force provided by the friction member 16 may bepositive or negative signs with the weight of the mounted displaydevice. In other words, although the elastic member 14 has a greatersecond resilient force, the shorter second positive force arm, which isresulted from the rotation of the sector gear 134, is used to compensatethe greater resilient force. Accordingly, the positive torque providedby the elastic member 14 is still substantially equal to the torque byapplying the net force of the weight of the mounted display device andthe friction force on the horizontal radius of the turning plate 130 sothat the position of the display device can be retained in a desiredposition.

In summary, the gear ratio (i.e., the relationship between the numbersof teeth on two gears or the relationship of between the circumferencesof two gears) of the smaller gear (i.e., the first gear 131) and thelarger gear (i.e., the second gear 132) is provided for reducing theturning revolution of the larger gear so that the elongation of thespring, which is connected to the larger gear, can be reduced. In otherwords, the driven larger gear has less turning revolution than thesmaller gear. Therefore, when the force is transmitted to the spring,the elongation of the spring is shorter than the movement distance ofthe display screen and the supporting holder 12. As a result, the spring(i.e., the elastic member 14) can be protected. Furthermore, the instantdisclosure provides a stepless stand due to the positive torque providedby the elastic member 14 is controlled and compensated equal to theweight of the mounted display device, and the mounted display device canbe located at a desired position.

The description above only illustrates exemplary embodiments andexamples of the instant disclosure. The instant disclosure shouldtherefore cover various modifications and variations made to theherein-described structure and operations of the instant disclosure,provided they fall within the scope of the instant disclosure as definedin the following appended claims.

1. An adjustable supporting stand, comprising: a main body; a slidablemodule disposed on the main body; a supporting holder, mounted on theslidable module, wherein the supporting holder slides relatively to themain body; a gear set, wherein the gear set has a first gear connectedto the supporting holder and a fourth gear coupled to the first gear,the first gear is assembled on a turning plate; and an elastic memberdisposed on the main body, wherein the elastic member has opposite firstend and second end, the first end is adjustably fixed on the main body,and the second end is connected to the fourth gear; when the slidablemodule is positioned in a first position, the elastic member has a firstresilient force, and the second end is located as the same horizontallevel with the rotary shaft of the fourth gear, the first resilientforce is applied on a first positive force arm; when slidable moduleslides from the first position downwardly and is positioned in a secondposition, the elastic member has a second resilient force, and thesecond resilient force is applied on a second positive force arm, thesecond resilient force is greater than the first resilient force, thesecond positive force arm is smaller than the first positive force arm.2. The adjustable supporting stand according to claim 1, wherein thefirst gear is smaller than the fourth gear, the first gear is smallerthan the turning plate.
 3. The adjustable supporting stand according toclaim 2, wherein the supporting holder further has a friction member,and the friction member contacts an inner surface of the main body. 4.The adjustable supporting stand according to claim 2, further comprisinga torque-adjusting member disposed on the main body, and the first endof the elastic member connects to the torque-adjusting member so as toadjust the torque of the elastic member.
 5. The adjustable supportingstand according to claim 2, further comprising a connection member,wherein the connection member is connected in between the turning plateand the supporting holder.
 6. The adjustable supporting stand accordingto claim 2, wherein the first gear and the turning plate rotatecoaxially.
 7. The adjustable supporting stand according to claim 2,wherein the slidable module includes two tracks, the supporting holderis slidably about the tracks.
 8. The adjustable supporting standaccording to claim 2, wherein at least one groove is defined by theslidable module and includes at least one slidable member, wherein thesupporting holder slides along the groove.
 9. The adjustable supportingstand according to claim 2, wherein the main body has a receiving room,and the slidable module, the gear set and the elastic member areaccommodated in the receiving room, and the supporting holder extendspartially outside the receiving room.
 10. The adjustable supportingstand according to claim 2, further comprising a gear set havingcoaxially rotating second and third gears, wherein the fourth gearengages with the third gear, the second gear engages with the firstgear, the first gear is smaller than the second gear, the third gear issmaller than the second gear.
 11. The adjustable supporting standaccording to claim 10, wherein the fourth gear is larger than the thirdgear.
 12. The adjustable supporting stand according to claim 2, whereinthe fourth gear has a pivoting shaft, and the second end of the elasticmember connects to the pivoting shaft.